Depending on how much you trust the PO and the shop he took it to, we might hold off on that. What I need to know is whether they bought new injectors or whether it is something that they picked off a junk car. IOW, is it NEW or used. If used, where did it come from? From FIC? No problem. From some car that has been sitting? Yeah, right. Also, what injectors? Are they stock size or under stock or over stock? We chased such an animal once years ago. They replaced it with the WRONG SIZE injectors.

http://fuelinjectorconnection.com/sh...p?productid=68

About $18.50.

 

Remove liknages. Remove the coolant hoses going to and from. Disconnect IAC. 4 bolts to take the throttle body off. After that, you take the top cover off and take the IAC housing off. Both of them torx bolts. After that, go get high by cleaning the TB, the passages, housing, etc, etc.

BE VERY CAREFUL WITH THE IAC. Unscrew and clean the pintle GENTLY. DO NOT PUSH OR PULL it.

I'd get new gaskets from GM if it were me.

 

Scanner would be good. I couldn't find anything wrong with my TPS once. Wire was broken and the ECM wasn't seeing the voltage that I saw. Scanner is better. You get data feed.

 

Maybe I should introduce you to my Vette's PO. He is a real good guy. His definition of "immaculate" leaves much to be desired. He hacked a button to crank the motor and called it a "Theft Deterrent". One of the runners was dented. And oh, get this. He put new shocks. How lovely. Cheap junk Koni, IIRC and he removed the bulb for the FX3 and the motors to the FX3 so I had to get them all over again. Pardon me if I don't believe what the PO says.

You have a point. Not sure how to check that unless you use a bore scope to see the engine condition? I wouldn't want to take the heads off unless I was sure. Perhaps you can monitor the O2 sensor and the knock counts to see if there is a knock that is caused by pre-ignition? Not sure how else besides to take the heads off or bore scope it to see.

I don't have MAF so I don't know what the value is but is there a way to read the values with a scanner? Maybe spray clean the MAF with cleaner? I'm not sure what the expected numbers are with MAF since my car is so removed from stock and SD.

 

According to Actron:

15: Coolant Temp Sensor
33: MAF Sensor High
34: MAF Sensor Low

Kinda beginning to look like the MAF is toast. Is someone near you where they can lend you a working sensor?

 

Well that is cheaper then I thought, TY for the link.

I think they installed them themselves, I bought it from a father/son who had 3 vette's total, they said they put in the injectors for better gas milage so it doesn't make sense really that they would have pulled some of a car when they had working stock ones, and it would be kinda a weird thing to lie about, especially when I never asked in the first place, they just mentioned it.

Didn't get around to the IAC today and if this week is anything like last week I will be busy working 50+ hours but I will have time at night to do some minor changes. Just happy this is my secondary vehicle lol

 

The Code 33 indicates either a faulty MAF sensor or a problem with the MAF burn-off circuit. Before replacing the MAF there are checks that can be done of the burn-off circuit. I will post the steps tomorrow. This is the part where you will need the voltmeter.

The Code 15 has to do with the ECM coolant temperature sensor. We'll deal with that after the MAF.

 

For now, hold off on any other troubleshooting. It's too easy to introduce new problems.

 

It's best to let troubleshooting run it's course. At this point it could be the MAF, burn-off module, wiring or relay. Or you could just skip troubleshooting and replace them all? And then replace the injectors just to make sure that's not a problem too.

 

Easiest way to check MAF is to borrow one for a quick test. Like I said, I have been burnt by the PO so I am suspicious but it could wait a bit if he feels they are good people.

 

Well I tried to take it into work today, made it about 1.5 miles, it is sitting on the side of the road now, its a safe place at least, I should be able to get it pulled back home.

But I couldn't get it to open up to the point where it doesnt run rich,couldn't get the RPM up over 25rpm once I put it in drive, couldn't drive faster then like 20. Pulled over started it up again, tried to accelerate again, ran the same so I pulled over again, now if I start it, it turns off and cuts off imeediately no matter what I do. I tried to isconnect the MAF connector and reconnect again, pulled the MAF and reconnected it, read codes had:
15,33,34 (Had not reset since I ran my test last night)

It may be hard for me to find someone to let me borrow a MAF, I'm guessing its a stretch on a AAP return policy to buy one (if they even have them in stores) and return it if it doesn't fix my problem.

 

Oh my...

D/C the MAF plug and LEAVE it d/c.
This forces the ECM into OL so the cal-pak can do the hard stuff. It's not going to run perfect BUT it WILL run purty good compared to what its been doing ! ! ! ya know, the burping, big gulping and choking...stinking of rich fuel...stumbling and trying to die. Hard to make it take throttle...all the signs of a failed MAF.

Yes, You have MAF issues.

85? you have a module in the dash IIRC...expensive lil sucker too...I might be wrong bout that. 85 or 86...I forget.

You need to get the FSM and go thru the test that the books outline and confirm the state of the MAF sensor & module. They are too expensive to just "go get another one" and HOPE that the new one does not get fried. The FSM has great flow charts that will take you thru the test that will prove the failed part. Do it that way.
The engine might be hard to start with the MAF unplugged. It WILL start and run eventually. Let it run rough....about 8 seconds of very very rich...then it will clear out, smooth out and be ok. The ECM has to see several seconds of this malfunction before it can find its way out and make a shift to a program that works.

You only have to do this once. It will try to run OK as long as things stay the same. SES lite will remain ON during this time.

Until you can prove what is at fault, drive with the maf plug d/c. This keeps it in OL and stuck in LHM so it will drive ok,. No worries....the instant that you plug in the replacement parts and it works,...the system recovers and shifts back to CL and normal.

Most important part of the whole deal...the FSM.
You need:

FSM
fuel test gauge
Noid lite
DVM
test lite
spark tester

Have fun and enjoy your car !

Oh yeah...

you need to locate and sterilize the harness ground wires...most important are the set on the block near the oil filter. Those are the engine control grounds. ECM grounds, fuel inj grounds.
This car does DOES not run on hot wires.. its controlled by grounds. learn them and how important they are to everything.
Again, NOT the battery cable ground. We want clean shiny harness grounds and whatever they contact. THAT determines how well the ECM gets its data to manage the engine.

Locate the jumper post behind the battery. That holds the important positive wires. Only the important stuff. Clean those like they were gold. It matters. You can make an engine stop misfiring just by cleaning those wires and the contact post...

EGR...get the vac line to the EGR and blow/suck on that line while the engine Idles. See which makes a difference. EGR is everything in this case. Harmless until it sticks open then it will make your car run like...YOUR car..
A sticky EGR has caused many men to go insane.....

Learn the FSM and the codes. These codes are the language the ECM uses to communicate with you. The ECM codes DO NOT TELL YOU WHAT IS WRONG.

They WILL tell you what systems are being effected by the failure...whatever that may be. Learning to interpret the ECM codes will take you far...

 

You don't need to borrow a MAF. Just follow the steps I'm going to give you and you will know what the problem is. First we are going to try a quick test to verify the MAF burn-off circuitry is functioning. You will need someone to help you.

1. Unlatch the spring clamps that attach the MAF to the air intake. Position the MAF so you can see the wires inside.
2. Turn ignition on (engine off)
3. On the ALDL connector under the dash (the port you get the codes from), connect terminal A to terminal E. Terminal E is on the top row 4 slots to the left of A.
4. Turn ignition off and immediately look at the MAF wire on the inside. After about 4 seconds it should glow. If it does, the burn-off circuitry is functioning properly. If it does not we will proceed with steps to isolate the problem in the circuitry.

Report back with the results.

 

I will have this done and get back to you by around 8-9 tonight (Eastern time)
Thanks!

 

Good luck. On a positive note, you have a repeatable problem. These are the easiest to troubleshoot. GM spent a lot of money embedding code conditions in the ECM firmware and then developing corresponding troubleshooting charts. You can typically isolate a problem without spending a dime.

 

Ok I am about to go run this test.

I went ahead and bought another MAF off craigslist, it was $50, thought it was worth the risk to get it off the road, but of course my lack of patience got the best of me, I picked the wrong one, well its not the same as the one in there now with a circuit board in the middle of the cylinder part and metal sensors, my new one has what looks like a wire triangle and no circuit board in the middle of the cylinder but it would fit I think so it could work.

FSM:
I got one! Finally!
April fools, well I did but it is for a 1987 vette, the guy I got the MAF from sold it to me for $30, so I said why not, I think there are not many differences.

 

Something to think about...you mentioned several posts ago that you changed the plugs and plug wires and the guy who helped you had "limited knowledge"...I suggest that you go back and check once, twice, thrice, (if neccesary) that you have the plug wires in the right order. I'm pretty experienced and last year I messed up a couple of my plug wires at the distributor towers...the car started just like new, and even sounded like it was firing on all 8 cylinders but I noticed a slight vibration in the motor. Sure enough I had a couple of wires in the wrong order. I was surprised at how well it ran with the crossed wires. I didn't drive it that way, so I don't know how poorly it would have performed on the road... Just a thought, but I agree with what many of the others have said - your MAF is suspect.

 

Frankly I'll be shocked if the MAF you picked up works. The MAF sensor is the most delicate sensor on the engine. Other forum members have gone through several replacement MAFs before finding one that works. At this point, we have not even verified the MAF is bad.

 

Sorry for the delay, I completed the test I DID NOT see any glow. I verified the pin connections and tried a few times, new saw anything.

 

Isn't there a stock value for MAF at idle? I would think so but since I don't have one, I don't know what it is off the top of my head. Do you? If he had a scanner he can read that output and see what it is.